mysqlblasy is a Perl script for automating MySQL
database backups. It uses "mysqldump" for dumping
mysql databases to the files sytem. It was written
with automated usage in mind. For example, it is
silent during operation, and only produces noise
on errors/problems. It rotates backups
automatically to prevent the backup disk from
getting full when the administrator is on vacation
(or is lazy).

runcronjobs processes the execution of centralized
cron jobs for a pool of servers. The cron jobs are
any executable files. runcronjobs runs cron jobs
located in a given directory if the current host
is specified as a target host for the jobs in
question. It allows you to centralize all the cron
jobs of a set of servers in a common shared
directory.

FcronQ is an Fcron GUI for Linux. Fcron is an advanced periodical command scheduler that aims to replace its predecessors. Current chronograph GUIs don't seem to support the advanced features offered by Fcron. FcronQ attempts to fill this void.

Schedule::Cron is a Perl module that provides a simple but complete cron-like scheduler. It can be used for periodically executing Perl subroutines. The philosophy behind Schedule::Cron is to call subroutines periodically from within one single Perl program instead of letting cron trigger several (possibly different) Perl scripts. Everything under one roof. Furthermore, Schedule::Cron provides a mechanism to create crontab entries dynamically, which isn't that easy with cron. It knows about all extensions (at least all extensions the author is aware of, i.e those of "Vixie" cron) for crontab entries like ranges including 'steps', specification of month and days of the week by name, or coexistence of lists and ranges in the same field. It even supports a bit more (like lists and ranges with symbolic names). It has existed since 1999 on CPAN and is successfully used in many projects.

Bidwell (named for Shelford Bidwell, the inventor of the first true fax machine way back in the late 1800s) is a set of Perl scripts that are designed to run as a cron job on a Unix-like system to download emails from a POP3 account and send their contents to a CUPS or lpr printer.

TimeMachine Scheduler is a Java scheduler which can scale and run a high volume of jobs with many different types of schedules, such as repeating on a fixed interval or based on cron expressions. The scheduler can control the job executions with thread pools, and it can persist job data into different storage receptacles. Users may use the built-in schedule server with an easy-to-use configuration file, or developers may use it as a library to extend the scheduler and write custom jobs, schedules, or user services.

cronbot is a wrapper script for cron jobs. Rather than running your job/script directly, you run it through cronbot, and it will allow a little more control to help keep things from getting out of hand. The default behavior is to only allow one instance of your job to run. This can be changed with the --duplicate option. You can also pass in a maximum time of execution for a job or add a random amount time to delay the start of your job. By default, jobs are run with a default "nice" value, which is usually 10.